add Unit test for Http.cs setting

Flow.Launcher.Test/HttpTest.cs

@@ -0,0 +1,33 @@
+using NUnit.Framework;
+using System;
+using System.Collections.Generic;
+using System.Text;
+using Flow.Launcher.Infrastructure.UserSettings;
+using Flow.Launcher.Infrastructure.Http;
+
+namespace Flow.Launcher.Test
+{
+    [TestFixture]
+    class HttpTest
+    {
+        [Test]
+        public void TestSettingUpdate()
+        {
+            HttpProxy proxy = new HttpProxy();
+            Http.Proxy = proxy;
+
+            proxy.Enabled = true;
+            proxy.Server = "127.0.0.1";
+            Assert.AreEqual(Http.WebProxy.Address, new Uri($"http://{proxy.Server}:{proxy.Port}"));
+            Assert.IsNull(Http.WebProxy.Credentials);
+
+            proxy.UserName = "test";
+            Assert.NotNull(Http.WebProxy.Credentials);
+            Assert.AreEqual(Http.WebProxy.Credentials.GetCredential(Http.WebProxy.Address, "Basic").UserName, proxy.UserName);
+            Assert.AreEqual(Http.WebProxy.Credentials.GetCredential(Http.WebProxy.Address, "Basic").Password, "");
+
+            proxy.Password = "test password";
+            Assert.AreEqual(Http.WebProxy.Credentials.GetCredential(Http.WebProxy.Address, "Basic").Password, proxy.Password);
+        }
+    }
+}